Air pollution continued to reach unhealthy levels in Bangkok, Thailand this morning (Feb 4) as a toxic cloud of smog covered the city.

Readings on the U.S. Air Quality Index (AQI) showed levels of toxic PM 2.5 particles in the atmosphere reaching 193 in some districts of the capital. Anything over 50 is considered unsafe.

Smog is at its worst in Thailand between January and March when farmers burn crops and there is a winter low-pressure system in which cold air is trapped closer to the ground by warm air above – preventing the pollution from being dispersed naturally.

The Thai government has been criticised for its handling of the country’s air pollution crisis – failing to tackle the problem for three consecutive years. Data scientist engineer Worasom Kundhikanjana said measures such as spraying water into the air were ineffective.

She said: ‘Unfortunately, this mitigation does not appear to be effective, since the volume of water is minuscule compared to actual rain.’

The Permanent Secretary of the Prime Minister’s Office, Teerapat Prayoonsit, said he has requested private companies and members of the public co-operate to reduce the levels of PM 2.5 in the air.